I have considerable experience with a wide range of gassers ranging from a Brison 2.4 through DA-100 twins but zero experience with smaller gassers. While I know there will be a weight difference, can anyone suggest a smaller gasser with performance similar to the OS 160 2 stroke?

I'm guessing that something like a Brillelli or Zenoah 26 might be close but I doubt they will match the OS. Maybe something in the 36 size would work but I really don't care for the Evolution or MVVS. My Brison 2.4 runs stronger than the OS but it is just a bit too large and heavy compared to the OS .... and the Brison is already employed elsewhere.

Any suggestions will be welcomed! I'm working on two projects ..... a 3D Super CUB ..... yes I said CUB and a 120 sized Sukhoi. Both would be perfectly powered by the OS 160 but I really want to go gas this time around.

Racer,
I think to get the comparable power, you need a light weight 35 to 40cc gaser. My rule of thumb is that the gaser should have about 50% more displacement then the glow engine. The Brison is on the heavy side with its Sach cylinder etc. Besides a cub has a short nose and liftinf air foil. Weight shouldn't be an issue, since it will be hanging on the prop most of the time.

Dave

[8D]

The MVVS 1.60 gasser comes very close, the MVVS 35 is equivalent in power, but has better torque for larger props.

My experience with large glow engines and small gassers is confined to a ST2300 and a CRRC pro GF26i. On paper the large tiger has more HP but in my opinion the 26 cc gasser beats it hands down. It delivers the power at lower rpm and moved my 11 pounds Extra with more authority. I think the OS 160 is a better engine than the ST3200, judging from its price, both are rated at 3.7 HP but deliver their peak power at different rpms, the OS having the advantage (9000 vs 1200 if I remember well).

I have used the 23cc ST engine with a large 18x8 prop, and it was very powerful at 7200 rpm, not in rated HP, but in real life performance.
HP ratings are a paper tiger. The MVVS gasser is rated at 3.8 hp, but these are factory test data with tuned pipe, set to best power, not best fit for use. In real life, operational hp of this gasser is about 3.0, slightly less than the operational power of the OS (prop 18x8 at 8200 for mvvs26 vs 8400 for the OS26 and this prop is too small at 9200 for the mvvs35). In switching to gas, a slight weight increase has to be accounted for as well. The tank can be smaller, but that does not completely compensate the added weight of ignition and battery.

Excellent info so far! Does anybody have real world info on the Brillelli 36? I know there was a long thread about it here in the forum but there has not been any new posts in awhile now. Most of the performance data there is about a year old now. I have not had a chance to call Scott to see if he is still producing the 36 or not. Its rear exhaust could be an advantage in narrow cowls.

Pe ..... you are making me take a 2nd look at the MVVS 35. Two things I don't like about this engine are its very small cooling fins and what appears to be a wimpy casting around the base of the carb. It doesn't appear to be very crash resistant and would require serious duct work for proper cooling. But then all engines are compromises and the front carb would sure make installation easier.

Engines are not built to be crash proof. In a crash that digs deep enough into the dirt, ALL front carb engines I have seen tore out the crankcase carb housing part. A dab of JBweld fixed it every time.
A rear carb engine will have the crank bent , twisted, or other damage.
The 35cc engine is an excellent choice, and has much mechanical reserves, and no engine has come to harm in normal use yet in the 7 years I sell them.
That is why the factory now has decided to expand it into a 40cc.

I have a Brillelli 36 that I'm starting to use for my 14.5 lb sea fury. I'm still in the break in stage with only one and a half tanks of fuel through it so far and not flown, but with what little I've found out, I've been impressed and I expect a lot more when it's broken in. With a 20 X 8 Xoar it'll nearly pull out of my hands holding it vertical. If you've been reading the Brillelli 36 thread you've probably already seen that people are settling on the 18 X 8 saying that the engine wakes up around 8000 rpm. You might check with Scott and see where he's at in production. He's been having some health problems and I think it's put him behind in production. Those that know him and his service have been patiently waiting. Those new customers that don't know him yet are getting frustrated and going elseware. If I needed another engine, I'd go back to him though.

Hi
We have a new engine GF40I,about 1300g, whould be a good choice for you to take palce 160 size glow engine !

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